Protective Effect And Mechanism Of Naringenin On Lipopolysaccharide Induced Acute Lung Injury In Mice

Objective:To investigate the protective effect of naringenin on acute lung injury in mice and its effect on SGK1 signaling pathway.Methods:The 15 Balb/C female mice were divided into 3 groups（n=5）:control group（Injection normal saline）,LPS group（induction of ALI model of drop in lipopolysaccharide 5μg/kg into the trachea）and LPS+Nar group（ALI model by insertion naringenin,100mg/kg,once a day,4 consecutive days）.Mice in each group were anesthetized 24h after modeling.PH,Pa O₂,Pa CO₂of each group were measured by blood gas analysis.The chest of each group were completely exposed,and bilateral lung tissues were taken out.The pathological changes and scores of the lung were observed by HE staining.The wet weight（W）and dry weight（D）of the tissue of the lower lobe of the right lung were measured,and the wet-dry weight ratio（W/D）was calculated using the measured values.TNF-α,IL-1βandα-ENAC,Na⁺-K⁺-ATPaseα1,p-SGK1 in lung tissues were detected by ELISA and WB,respectively.Results:1.The alveolar structure of Control group was intact and clear.In LPS group,alveolar structure was damaged and broken,and alveolar septum was widened and a large number of inflammatory cells were infiltrated.The pathological changes of LPS+Nar group were between LPS group and Control group.Most alveolar structures were intact and inflammatory cells were decreased.2.Compared to the control group,the PH and Pa O₂in blood were decreased,and theα-ENAC,Na⁺-K⁺-ATPaseα1,p-SGK1 protein in pulmonary tissues were decreased in LPS group（P<0.05）.However,the Pa CO_2,W/D,TNF-αand IL-1βwere all increased（P<0.05）.Compared with the LPS group,the PH and Pa O₂in blood were increased,and the expression ofα-ENAC,Na⁺-K⁺-ATPaseα1,p-SGK1 in pulmonary tissues were increased in LPS+Nar group（P<0.05）.However,the Pa CO₂,W/D,TNF-αand IL-1βwere decreased（P<0.05）.Conclusion:1.Naringenin alleviated lung damage,decreased W/D value,inhibited TNF-αand IL-1βrelease,up-regulated the expression ofα-ENAC and Na⁺-K⁺-ATPaseα1 in alveolar epithelium,and had protective effect on ALI mice induced by lipopolysaccharide.2.The protective effect of naringenin on ALI mice may be related to the activation of SGK1 signaling pathway,which may be a new target for the treatment of ALI.3.Naringenin may be a new treatment method for ALI.